// Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'package:kernel/ast.dart';
import 'package:kernel/core_types.dart';
import 'dart:core';

import 'package:vm/transformations/specializer/factory_specializer.dart';

/// Replaces invocation of Map factory constructors with
/// factories of VM-specific classes.
/// new LinkedHashMap<K, V>() => new _InternalLinkedHashMap<K, V>()
class MapFactorySpecializer extends BaseSpecializer {
  final Procedure _linkedHashMapDefaultFactory;
  final Constructor _internalLinkedHashMapConstructor;

  MapFactorySpecializer(CoreTypes coreTypes)
      : _linkedHashMapDefaultFactory = assertNotNull(
          coreTypes.index.getProcedure(
            'dart:collection',
            'LinkedHashMap',
            '',
          ),
        ),
        _internalLinkedHashMapConstructor = assertNotNull(
          coreTypes.index.getConstructor(
            'dart:collection',
            '_InternalLinkedHashMap',
            '',
          ),
        ) {
    transformers.addAll({
      _linkedHashMapDefaultFactory: transformLinkedHashMap,
    });
  }

  static T assertNotNull<T>(T t) {
    assert(t != null);
    return t;
  }

  TreeNode transformLinkedHashMap(StaticInvocation node) {
    final args = node.arguments;
    if (args.named.isEmpty) {
      return ConstructorInvocation(
        _internalLinkedHashMapConstructor,
        Arguments([], types: args.types),
      )..fileOffset = node.fileOffset;
    }

    return node;
  }
}